Adventist Youth Honors Answer Book/Lashing/Shear
Sheer lashing uses two or three spars or poles, 15 - 20 feet of rope.
To tie a sheer lashing, lay the two poles side-by-side and parallel to one another. Tie a clove hitch around one spar. Then wrap the free end of the rope around both spars about seven or eight times. Pull them as tight as you can. Then make three fraps around the lashing, and again, pull the rope as tight as you can. Finally, tie a clove hitch on the second spar.
To use sheer lashing around with three poles, lay all three poles side by side and parallel to one another. Tie a clove hitch on one pole, and wrap the rope around all three seven or eight times. Pull the rope tight. Make three fraps between two of the poles, then cross over and make three more between the other two poles. Pull the frapping as tight as you can and finish it off with a clove hitch.